Prefabricated flooring and charging buggy trackway for open hearth furnaces



Aug. 10, 1965 R. MILLER 3,199,855

PREFABRICATED FLOORING AND CHARGING BUGGY TRACKWAY FOR OPEN HEARTH FURNACES Flled May ll, 1962 2 Sheets-Sheet l A E1-'a1 Attorney g Aug. 10, 1965 R. MILLER PREFABRICATED FLOORING AND CHARGING BUGGY TRACKWAY FOR OPEN HEARTH FURNACES 2 Sheets-Sheet 2 Filed May 11, 1962 RR I m. a m.. la. E a a R k W wm .m WM. Q\\W. QM@ y MM, W EN.. mm VVV im. A Amm Nlhrwml ...EH vm R.. LFE ,R m vm \/Q\ vm M 5. 3... .i as..- .fjljlj J R :\w .E E E .mmunmwwnnnu y um.; Il mLuImr m Lw y. a ww n n vm m n m h mm mm. /HH.\/\/ N Hmw mw @mmm f/H n www J Q mw P m n). 2/ m km. /VVMf Y United States Patent O Chicago, lli, assigner to United States This invention resides in the portion of open hearth furnace flooring in which the charging buggy trackway is located and is directed to improvements that facilitate its repair. More specifically, it comprises a prefabricated and reinforced concrete slab that is installed in position to form a portion of the furnace floor and the charging bugg trackway. While especially adapted for the repair of existing facilities, the invention is also applicable to the construction of new facilities in which a charging buggy trackway may be constructed by assembling a plurality of the prefabricated slabs of this invention in endto-end position on the furnace iioor. Such slabs, as indicated, may also be used in the repair of sections of the buggy trackway and flooring in existing facilities that are constructed in a conventional manner and become worn out or damaged in operation.

The portion of the furnace floor with which this invention is concerned is located in front of the furnace doors and includes the trackway rails over which the charging buggies or cars travel. The charging buggies are used to transport charging boxes to positions in front of the furnace doors in which they may be inserted by a charging machine through the doors of a furnace and their contents of lime, iron ore, or other materials going to make up the furnace charge emptied into the furnace. The buggy trackway rails are part of the furnace flooring which is formed of concrete and is poured in position on steel plates carried by underlying steel beams to which the tracliway rails are also secured by rail clamps or other fastening devices.

The furnace floor, particularly in the area about the charghig buggy trackway rails, is subject to adverse operating conditions of a nature that require frequent repair and replacement. Rail repair and replacement re also necessitated by break-outs or eruptions of molten metal onto the floor in front of the furnace. When this occurs the molten steel ows over the rails and downwardly into any space between the sides thereof and the concrete tlooring where it is trapped under the head of the rail. Subsequent removal of the scrap metal by a crane or other equipment frequently results in the rail being pulled away from the beams on which it is supported. The entrapment of metal under the head of a rail in this manner is further apt to result in a fused connection that prevents any possibility of the scrap being removed without pulling the rail with it. The repair and replacement of rails that is necessitated by metal spillage of this character as well as from normal wear is a troublesome problem in open hearth operations ince repairs at one of the furnaces in an open hearth shop will interfere with charging operations in other furnaces.

One of the principal objects of this invention, as indicated, is to facilitate the repair and replacement of the trackway rails for charging buggies and the portion of the furnace floor in which they are locate l. To this end, the invention comprises a prefabricated and reinforced concrete slab that includes a pair of laterally spaced parallel rails extending longitudinally betr/veen opposite ends thereof and may be assembled on the furnace floor beams to form a portion of the furnace flooring and the charging buggy trackway.

Another object of the invention is to provide an imldd Patented Aug. it), P355 ICC proved rail for charging buggy tracliways that dispenses with the standard rail heads and consequently reduces the possibility of the rail being pulled loose from the furnace beams upon removal of scrap metal that is spilled from the furnace onto the furnace iiooring. A related object is to provide a rail in the form of an inverted T- section that is formed by splitting a wide square-hanged H-beam.

Other objects and advantages of the invention will become apparent from the followirn description and the accompanying drawings.

In the drawings, there is shown a preferred embodiment ofthe invention. In this showing:

FIGURE l is a plan view that shows somewhat diagrammatically the manner in which the prefabricated sections of this invention are assembled in the flooring of an open hearth furnace to form a portion of the charging buggy trackway thereof;

FIGURE 2 is a plan view on an enlarged scale of one of the prefabricated flooring sections shown in FIGURE l, a central portion thereof being broken away;

FIGURE 3 is a transverse sectional view taken along the line lll-III of FIGURE 2;

FIGURES 4 and 5 are sectional views taken respectively along the lines IV-IV and V--V of FIGURE l;

FIGURE 6 is a plan view of the joint bar connection between adjacent rail ends shown in FIGURE 5;

FIGURE 7 is a side elevation of the connection shown in FIGURE 6; and

FIGURES 8 and 9 are sectional views taken respectively along the lines VIII- VIII and IX-lX of FIG- URE 7.

FIGURE l shows the general arrangement of a charging buggy trackway l between the trackway rails 2 for a charging machine and a battery of open hearth furnaces 3 that have the usual doors l on the charging side thereof. The portion of the furnace Hoor adjacent the doors 4 and the buggy trackway l therein is, in accordance with the principles of this invention, comprised of prefabricated reinforced concrete slabs or inserts 5. The edge portion of the slab 5 in front of the center door l of each furnace is removed to provide an opening 6 through which slag may be removed from the furnace by flushing. Each slab 5 has a pair of laterally spaced parallel rails 7 extending longitudinally between opposite ends thereof that t into and form part of the charging buggy trackway l when it is assembled in the door of the furnace in a manner to be described.

As best shown in FIGURE 3 the traclrway rails '7 are T-sections that are formed by splitting a square-flanged H-beam along a line centrally between its franges. They are mounted in an inverted position with their horizontal flanges 8 welded or otherwise rigidly secured to a bottom plate 9 and their legs l0 projecting vertically upwardly. The upper ends of the legs 1li provide surfaces 1l over which the flanged wheels of the charging buggies travel. The surfaces l1 may be hardened by applying weld rod (not shown) thereto. Attention is particularly directed to the fact that the legs it) of rails 7 formed from a I`- section in this manner have the same transverse dimension at all points between the surfaces 1l and the flanges S and thus do not have any projecting parts under which molten metal spilling out of the furnace can lodge and anchor itself upon cooling. The legs l@ further have a greater thickness compared to the webs of standard rails and are thus more eective in chilling and dissipating the heat of molten metal so that there is less possibility of its fusing to the rail.

ri`he bottom plate 9 is rectangular and has upwardly projecting vertical flanges i2 along the sides and ends thereof that are formed by welding angles 13 about its peripheral edges 14. The horizontal bottom fianges 15 of the angles 13 extend beyond the bottom plate edges 14 for a purpose to be described. Laterally spaced openings 16 in the fianges 12 at the ends of each section provide for connection of the rails 7 into the charging buggy trackway 1 by joint bars in a manner also to be described.

After assembly of the rails 7 and angles 13 on the bottom plate 9, concrete 17 is poured on the bottom plate 9 in the space between the fianges 12, the bottom plate 9 and f'iauges 12 forming an upwardly open pan in which the concrete is received. The upper surface 18 of the concrete 17 provides a smooth fioor surface that is level with the upper edges 11 of the rails 7, but has a bevel or chamfer 19 along facing sides of the rails 7 that provides space through which the flanges of the charging buggy wheelstravelling `over the rails may move. The concrete 17 is preferably one that will stand up under high temperatures such as are encountered when metal spills from the furnace onto its surface 18. For this purpose it may be formed of any suitable high heat resistant cement having a high alumina content and crushed hre brick aggregate. Since the slabs are prefabricated the concrete 17 is poured at a location away from the furnace and the required forming and curing techniques can be applied to obtain maximum heat resistant properties and a smoother oor surface 18 than is possible where the concrete is poured in place on the furnace floor. As shown in FIGURE 4, vertical studs 2G may be welded to the bottom plate 9 for anchoring the concrete 17 more securely in position thereon. In addition, wire mesh screen 21 having welded connections at its ends with a pair of spaced anchoring studs 20 may be provided for improving the anchoring connection of the concrete 17 on the bottom plate 9.

As shown in FIGURES 4 and 5 of the drawings, the door is supported on parallel beams 22 that extend transversely with respect to land project outwardly from thev side wall 23 of the furnace 3. The beams 22 in turn are supported on transversely extending Stringer beams 24 and track Stringer beams 25 that are arranged underneath and extend transversely with respect to the floor beams 22. The permanent portion of the furnace oor in which the charging machine trackway rails 2 are located is formed of concrete 26 poured on a horizontal plate 27 that is secured to the floor beams 22. Retaining angles 2S are welded to the plate 27 and define the edges of the permanent concrete fioor 26. The Prefabricated slabs 5 of this invention are supported on the beams 22 in the space between the retaining angles 28 and the furnace side wall 23. The horizontal anges 29 of the retaining angles 28 project toward the peripheral edges 4 of the bottom plate 9 and into the space underneath the horizontal flanges of the angles 13, which as stated above project beyond the peripheral edges 14 0f the plate 9 to provide for this overlapping arrangement of the flanges 15 and 29. Angular fastening clips 3i? are welded to the vertical slab anges 12 and the 'horizontal flanges 29 of the retaining angles 28 to secure the slabs 5 against movement with respect to the permanent portion of the furnace floor. 9 may have bolted or clamping connections (not shown) with the oor beams 22 to secure the slabs 5 against movement thereon. After the clips 30 are welded'in position the space between theV vertical flanges 12 and 23 is filled with concrete. The space between the slabs 5 and the side wall 23 of the furnace is also filled with concrete that is poured on a plate 31 that has its opposite edges supported on the beams 22 and the furnace side wall 23.

Opposite ends of the rails 7 in each of the slabs 5 have drilled openings 32 for the reception of fastening bolts to provide for their connection by joint bars to the ends of adjacent rails. When a slab 5 is used for the repair of an existing traclrway 1 formed of standard rails 33, a joint bar 34 constructed as shown in FIGURES 5-9 is used.

In addition, the slab bottom plates Y ing bolts.

The bar 34 has one end 35 that is standard and fits between the head 35 and the base 37 of the rail 33 against its web 38, the rail and joint bar having aligned openings 32 for the reception of fastening bolts. The other end 39 of the joint bar 3d is a flat strip that fits against the vcrtical leg 19 of the rail 7 and has openings aligned with the openings 32 in the rail for the reception of the fasten- When the slabs 5 are arranged in end-to-eud relation as shown in FIGURE l, both ends of the joint bar are the same and have the shape and construction of the end 39 shown in FlGURES 5 and 6.

From the foregoing, it will be apparent that the slabs 5 enable repair of a charging buggy trackway in a minimum of time and thus reduce costly furnace operating delays. When used for repairing conventional trackways that are constructed with standard rails, the damaged portion of the trackway and furnace oor is cut away so that one or more of the prefabricated slabs may be assembled on the floor beams with the ends of the rails in the repair slab connected in and forming part of the trackway rails. In addition to their use for repair purposes, the slabs as described above may be assembled in end-to-end positions in the construction of a charging buggy trackway in new furnaces, which can thereafter be readily repaired by replacing the slabs 5 therein as needed. Attention is furthere directed to the fact that the improved heat resisting properties of the slabs 5 which is obtained through their prefabrication and the consequent application of proper curing techniques for the concrete together with the inverted T-shape of the rails 7 cooperate to reduce the repairs necessitated by molten metal flowing onto the surface of the trackway 1. The slabs 5 thus act both to reduce the time required for repairs and the frequency of such repairs.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. In a charging buggy trackway and flooring for open hearth furnaces of the type having floor beams projecting outwardly from the charging side thereof, the combination with said floor beams of a plurality of prefabricated concrete slabs respectively having a pair of laterally spaced parallel rails extending longitudinally between opposite ends thereof, said slabs being supported on said beams in end-to-end positions in which the said rails therein cooperate to form a trackway for the movement of charging buggies along the charging side of said furnace, and means including tie plates fastening opposite ends of said rails in said buggy trackway.

2. A prefabricated insert for the portion of an open hearth furnace floor in which the charging buggy trackway is located comprising a horizontal base plate, a pair of trackway rails secured to said base plate in parallel positions and extending between opposite ends thereof, and a covering layer of concrete over the area of said base plate between and outwardly with respect to said rails, said insert being adapted for mounting in a position in which said rails form part of the charging buggy trackway and said concrete forms part of the furnace oor.

3. An open hearth furnace floor insert as defined in claim 2 characterized by said base plate having Vertical fianges about its peripheral edges forming a margin for said concrete.

4. An insert as defined in claim 2 characterized by each of said rails comprising an inverted T-section having its horizontal flange welded to said base plate and in which the upper edge of its vertical leg forms the rail head over which the charging buggies travel.

5. An insert as defined in claim 2 characterized by said base plate having studs projecting upwardly for anchoring said concrete thereto.

6. An insert as defined in claim 5 characterized by 5 reinforcing wire mesh extending between pairs of said studs.

'7. A prefabricated insert for the portion of an open hearth furnace floor in which the charging buggy track- Way is located comprising a steel pan including a rectangular base plate having upwardly projecting flanges along the sides and ends thereof, a pair of trackway rails secured to said base plate in parallel positions and extending between opposite ends thereof, the said pan franges along the said opposite ends of said base plate being interrupted to provide openings for the connection of said rails in said buggy trackway, and a lling of concrete in said pan covering the area of said base plate between and outwardly with respect to said rails, said pan being adapted for mounting in a position in which said rails form part of said buggy trackway and said concrete forms part of the said furnace door.

S. A Prefabricated furnace oor and buggy trackway insert of the character described in claim i characterized by said anges comprising steel angles along the peripheral edges of said base plate.

References Cited by the Examiner UNITED STATES PATENTS 8/38 Morton 266-33 2,551,278 5/51 Millan 266-13 2,836,309 5/58 McFeaters.

FOREIGN PATENTS 817,956 8/ 59 Great Britain.

MORRS O. YWCLK, Primary Examiner.

DELBERT E. GANTZ, Examiner. 

1. IN A CHARGING BUGGY TRACKWAY AND FLOORING FOR OPEN HEARTH FURNACES OF THE TYPE HAVING FLOOR BEAMS PROJECTING OUTWARDLY FROM THE CHARGING SIDE THEREOF, THE COMBINATION WITH SAID FLOOR BEAMS OF A PLURALITY OF PREFABRICATED CONCRETE SLABS RESPECTIVELY HAVING A PAIR OF LATERALLY SPACED PARALLEL RAILS EXTENDING LONGITUDINALLY BETWEEN OPPOSITE ENDS THEREOF, SAID SLABS BEING SUPPORTED ON SAID BEAMS IN END-TO-END POSITIONS IN WHICH THE SAID RAILS THEREIN COOPERATE TO FORM A TRACKWAY FOR THE MOVEMENT OF CHARGING BUGGIES ALONG THE CHARGING SIDE OF SAID FURNACE, AND MEANS INCLUDING TIE PLATES FASTENING OPPOSITE ENDS OF SAID RAILS IN SAID BUGGY TRACKWAY. 